METALLIC FIBER REINFORCED CONCRETE: EFFECT OF FIBER ASPECT RATIO ON THE FLEXURAL PROPERTIES

Abstract

Since many decades efforts have been made to reduce the brittleness of cementitious materials by the use of micro and macro fibers of different mechanical, geometrical and physical properties. This contribution presents the results of an experimental investigation carried out to study the effect of fiber aspect ratio on the flexural properties of metallic fiber reinforced concrete (MFRC). The flexural properties, which have been studied, include maximum load bearing capacity (peak load), post-crack strength and flexural toughness. High performance metallic fibers of different aspect ratios were used. The dosage of fibers was kept 20 kg/m3 (0.25 % by volume fraction) for all the fibered concrete mixtures. Three point bending tests were performed on both control (without fibers) and fibered notched prismatic concrete specimens of cross section 100 x 100mm and clear span of 450mm. The results showed that the flexural properties of concrete matrix are significantly improved by the addition of high performance metallic fibers. Moreover, it was found that the level of improvement in flexural properties of MFRC varies with the aspect ratio of fibers. Out of the two different aspect ratios of metallic fibers used in this study, the fibers with larger aspect ratio showed better efficiency in improving the flexural response of MFRC.